Standoff (2006)

S6E14 Dora's Enchanted Forest Adventures (2): The Secret of Atlantis

Dora, Boots, Diego, and King Unicornio embark on a quest beyond the Enchanted Forest to resolve a long-standing conflict between the unicorns and dragons, while also seeking to rescue the fabled continent of Atlantis. Meanwhile, a selfish owl seizes the chance to become the ruler of the forest, creating chaos in the magical realm.